Composite sheathing materials are widely used in the building and construction industries as roof components or panels, for sheathing the surfaces which form the exterior roof of a building. Such sheathing materials may be exposed to liquid water from rain or melting snow. Preferred sheathing materials prevent the passage of liquid water from the exterior to the interior of the building, while also providing Class C fire resistance to the roof structure. Conventional composite sheathing materials, while preventing the passage of liquid water therethrough, typically are manufactured from wood and bituminous components which may easily catch fire which spreads to the remaining building structure.
It would be desirable to prepare a composite sheathing material that would substantially prevent the passage therethrough of liquid water while also providing a Class C fire resistance rating to the roof structure.